The California Rice Commission’s (CRC) salmon pilot project has now entered its second year and is making steady progress in data collection. The $1.4 million project is aimed at improving salmon populations through providing a healthy habitat and food source for the fish in California rice fields. The project is largely being funded through USDA’s Natural Resources Conservation Service (NRCS) in an effort to develop the process on a larger scale in the future.
“We want to answer all the questions that we need to answer about what exactly is it that we need the growers to do. Is it a physical modification of the field? Is it an alteration of how they flood the field, how they drain the field, the timing of drainage?” said Paul Buttner, CRC Manager of Environmental Affairs. “These are all the questions that we need to answer in order to work with NRCS to develop that conservation management practice.”
The salmon that are reared in winter-flooded rice fields are released and tracked on their way out to the Pacific Ocean using Juvenile Salmon Acoustic Telemetry (JSAT) tags that are surgically inserted into the fish. The researchers have been working in eight rice plots evaluating four practices and utilizing four control plots. One field includes deep channels, another includes vegetative structures, one field includes both deep channeling and vegetative cover, and another involves no special treatment.
“We put approximately 9,000 fish in these eight fields – so about 1,000 fish per field – and those fish were free-swimming. So, we’re able to utilize them to test out the effectiveness of our treatments. We also had a number of caged fish as well” Buttner explained. “Those are the ones that we would eventually put that JSAT tag into and they would give us all the information as to their survivability out through the Golden Gate.”
Salmon that are released and tracked as they move out to the ocean alternate between fish reared in rice fields and fish that are reared in hatcheries. The paired release study provides important data as to how the time spent in rice fields may ultimately benefit the salmon. “We want to see the comparison as to whether more or less of our rice field fish get out to the Golden Gate as compared to an equal number of fish that do not enjoy the growth in the flood plain but rather mimic fish that would go directly from the hatchery into the river,” said Buttner.
The California rice industry has a long history of implementing various conservation practices, with tremendous work done to improve habitat for birds over the past few decades. Using the rice fields as “surrogate wetlands” for salmon provides significant potential for carrying on that tradition. “The Sacramento Valley is a very special place,” Buttner noted, “We want to make sure that that legacy is continued.”
CRC has also set up a provisional means of tracking the salmon as they make their way through the water system out through Golden Gate. As of April 10, three percent of the fish that were recently released were already out past Benicia. NRCS has provided nearly half of the funding necessary for the salmon pilot project, with another third of the overall support being provided by Syngenta Crop Protection, LLC. Other significant contributors to the project include the Almond Board of California, Corteva Agriscience, Valent, and Grow West.